The first interconnection of the LHC. A welder is seen making the very first interconnection between two cryomagnets for the LHC. The 1700 interconnections between superconducting magnets for the whole collider will require 123 000 separate welding and assembly operations. May 2005Photo #: 0505004_02

First LHC magnets installed. The first magnets have been installed in the LHC tunnel but are yet to be connected. Technicians must inspect the magnets before the connections are made. April 2005Photo #: 0504028_10

The first interconnection of the LHC. A welder is seen making the very first interconnection between two cryomagnets for the LHC. The 1700 interconnections between superconducting magnets for the whole collider will require 123 000 separate welding and assembly operations. May 2005Photo #: 0505004_07

Installation of the cryogenic distribution line (QRL) on sector 1-2, the last to be equipped. Installation of a single sector involves placing 325 elements and making almost 2000 internal welds. May 2006Photo #: 0605016_01

Installation of the cryogenic distribution line (QRL) on sector 1-2, the last to be equipped. Installation of a single sector involves placing 325 elements and making almost 2000 internal welds. May 2006Photo #: 0605016_02

Installation of the cryo-magnets for the LHC passed the symbolic 1000 mark at the beginning of the month. At 10.30 am on 5 September, the 1000th cryo-magnet was installed in the LHC tunnel in the arc between point 3 and point 4. The same week also saw the completion of the cryo-magnet installation between point 8 and point 1, making this the first sector where all the magnets have been installed. Three other sectors (7-8, 4-5 and 5-6) are very close to completion with only a very few magnets missing, and installation work is now concentrated on sectors 3-4 and 6-7. There are a total of 1746 cryo-magnets altogether, of which 1232 are the well known blue dipoles. The remaining 746 cryo-magnets should be transported and installed by March 2007. Installation in the LHC tunnel is only one of many successive steps in the life of a cryo-magnet: cold mass manufacturing, cryostating, magnet testing at low temperature, preparation before lowering, transport, interconnecting, pumping down, cooling down and commissioning before injecting the first protons beams. Hundreds of collaborators, both from CERN and from the contractors, have been working hard for many years and should be warmly thanked for achieving this milestone. September 2006Photo #: bul-pho-2006-036

A worker inside the LHC tunnel. Technicians and engineers worked days and nights, carefully installing 20 magnets a week between 7 March 2005 and 26 April 2006. Each dipole weighs 34 tonnes and is 15 m long. Once they have been lowered down the specially constructed shaft, they begin a slow progression to their final destinations in the LHC tunnel, taking about 10 hours to arrive at the furthest point on the LHC ring. June 2006Photo #: 0606036_01

Descent of the last LHC dipole magnet. The last of 1746 superconducting magnets is lowered into the LHC tunnel via a specially constructed pit at 12:00 on 26 April. This 15-m long dipole magnet is one of 1232 dipoles positioned around the 27-km circumference of the collider. Dipole magnets produce a magnetic field that bends the particle beams around the circular accelerator. April 2007Photo #: 0704009_03

Descent of the last LHC dipole magnet. The last of 1746 superconducting magnets is lowered into the LHC tunnel via a specially constructed pit at 12:00 on 26 April. This 15-m long dipole magnet is one of 1232 dipoles positioned around the 27-km circumference of the collider. Dipole magnets produce a magnetic field that bends the particle beams around the circular accelerator. April 2007Photo #: 0704009_06

Getting around the LHC. In order for technicians to get around the 27-km tunnel that houses the LHC various methods of transportation must be employed. Here the optical-guided transport system is seen being utilized. October 2005Photo #: 0510028_02

Transporting the first LHC superconducting magnet. The first superconducting magnet is transported to its final location in the LHC tunnel using a specially designed vehicle. The 15-m long dipole magnet must be moved to its assigned location in the tunnel before it can be unloaded and installed. March 2005Photo #: 0503013_08

First LHC module of four superconducting cavities. One of the superconducting modules consisting of four cavities that will supply 400 MHz radio-frequency power to accelerate the particles in CERN’s LHC collider. September 2000Photo #: 0009014_01

First LHC module of four superconducting cavities. One of the superconducting modules consisting of four cavities that will supply 400 MHz radio-frequency power to accelerate the particles in CERN’s LHC collider. September 2000Photo #: 0009014_02

First LHC module of four superconducting cavities. One of the superconducting modules consisting of four cavities that will supply 400 MHz radio-frequency power to accelerate the particles in CERN’s LHC collider. September 2000Photo #: 0009014_03

The prototype LHC full cell during test. Prototype superconducting magnets for CERN’s LHC collider under test in the String 2 test facility. The tests simulate many months of LHC running. May 2001Photo #: 0105037_01

The prototype LHC full cell during test. Prototype superconducting magnets for CERN’s LHC collider under test in the String 2 test facility. The tests simulate many months of LHC running. May 2001Photo #: 0105037_02

Computer-generated diagram of an LHC dipole. This computer-generated image of an LHC dipole magnet shows some of the parts vital for the operation of these components. The magnets must be cooled to 1.9 K (less than –270.3°C) so that the superconducting coils can produce the required 8 T magnetic field strength. September 1998Photo #: 9809007

The four main LHC experiments. This diagram shows the locations of the four main experiments (ALICE, ATLAS, CMS and LHCb) that will take place at the LHC. Located between 50 m and 150 m underground, huge caverns have been excavated to house the giant detectors. The SPS, the final link in the pre-acceleration chain, and its connection tunnels to the LHC are also shown. June 1999Photo #: 9906026_01